No crank, no start. Out of ideas.

Jrad1337

Jrad1337

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Denver, Colorado
2006 LJ Rubicon will not crank from the ignition, I get dash lights, nothing else, no relay clicking, no power to starter, here is how I’ve troubleshot so far. The short term goal is just cranking with key.

-Multimeter on battery, tests good @ 12v

-jumped starter relay, engine cranked
battery/starter working.

-Checked all relays by switching them with horn and honking, relays working.

-Checked clutch safety switch with multimeter, working.

-Rebuilt Ignition from cylinder to switch after recovering from thief drilling it, cycles fine.

-Ignition harness probed and tested for power, power coming out when key is turned.

-Checked and cleaned engine block and firewall grounds.

Short of ripping the entire thing apart to thoroughly check all wiring from ignition to relay, does anyone have any other ideas?

-Jarret
 
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Jrad1337 said:
2006 LJ Rubicon will not crank from the ignition, I get dash lights, nothing else, no relay clicking, no power to starter, here is how I’ve troubleshot so far. The short term goal is just cranking with key.

-Multimeter on battery, tests good @ 12v

-jumped starter relay, engine cranked
battery/starter working.

-Checked all relays by switching them with horn and honking, relays working.

-Checked clutch safety switch with multimeter, working.

-Rebuilt Ignition from cylinder to switch after recovering from thief drilling it, cycles fine.

-Ignition harness probed and tested for power, power coming out when key is turned.

-Checked and cleaned engine block and firewall grounds.

Short of ripping the entire thing apart to thoroughly check all wiring from ignition to relay, does anyone have any other ideas?

-Jarret
Click to expand...

I know it sounds silly but have you also tried tapping on the starter while you're trying to crank it with the key? My grand cherokee I used to have did this to me alot and I would have to have someone tap on the starter to get it to work until I went and bought a new starter. If it does try to start when you're tapping on it I'm gonna say your starter / starter solenoid might be the issue but I'm not 100% sure. I hope this helps in any manner!
 
I think your problem is all in the column... have you inspected the ignition switch actuator? Do you get voltage out in the START position of the ignition? If the actuator is bad, you may get the run and accy positions, but the start will not engage.

On mine (the Jeep has always been in high humidity areas) the actual contacts in the ign switch were dirty, so after a careful disassembly and cleaning, it was fully operational again... I had your same symptoms...
 
I've owned about 40 vehicles in my lifetime. I'm an accomplished shadetree mechanic having swapped and rebuilt a 350 SBC, a 283 SBC, a 22RE, a porsche 912 motor, several transmissions, and gobs of other big bolt on or fab projects like lift kits, bumpers, cages, etc. My opinion, for what it's worth, is that sometimes, it's best to let fresh eyes take a look.

Personally, I think you've done your part to find a simple, reasonable fix. Good job!! Have a beer or your cold drink of choice and take a breather.

I think it's ok to consider towing it to a trusted shop and letting them have a few hours shop time to diagnose and fix.

BTW, welcome to the forum!
 
Reading through your post, I am sorry for your dilemmas! Wiring in Jeeps can be, odd, shall we say, sometimes. You've done most of the troubleshooting you could - and I think you've actually narrowed it down to where the problem is. If the starter has power, and functions when jumped - we know it's not the starter. If your column has power and seems to be functioning correctly, probably not that either. If the relay is working, probably not there. Think of it like a human - the brain works, and the hand works - but the nerves connecting them are shot. I would be very willing to bet that your problem lies somewhere in the wiring between the column and the starter. It also sounds like you've had an issue with thieves (that's one reason why I'm glad I've got a 5spd lol) - it still could have something to do with damage done during that process that you just can't see - maybe a wire got cooked or smashed and is grounding out. I think your only option is to get ahold of a good wiring diagram and chase some cable.
 
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Have you had a look at the wiring diagram in the FSM (found in the resources section here) to start tracing wires & testing the intermediate components in the circuit? You know where you have power....keep following that until you lose power. I wouldn't take it to a shop just yet (read: ever).
 
Sorry to leave you hanging, I haven’t gotten any further with diagnosing the electrical issue, after looking at the FSM and proving the wiring loom diagram incorrect I was a bit discouraged and decided to take a break with the electrical. For the past few weeks I’ve put my energy into restoring the interior as it needed some TLC as well. I’ve contacted a few shops but I’m not sure what route to end up taking. I will most likely chase some cable before I tow it somewhere, but I’d by lying if I said I’m not fed up with it.
 
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Jrad1337 said:
I’d by lying if I said I’m not fed up with it.
Click to expand...

We've all been there. The good news is that the ignition/starter circuit isn't too bad to chase down, and it doesn't involve the computer. But sometimes it's best to step away and come back with a clear head and renewed vigor.
 
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Go back and remove the ignition repair you did. Then dig a little further into it looking for other damage that may not have been very obvious and could have been missed the first time. With a drill bit being in there there could be damaged wiring or connectors, metal fragments, damage to other parts such as ignition switch actuator pin.
 
Mac57 said:
Go back and remove the ignition repair you did. Then dig a little further into it looking for other damage that may not have been very obvious and could have been missed the first time. With a drill bit being in there there could be damaged wiring or connectors, metal fragments, damage to other parts such as ignition switch actuator pin.
Click to expand...

That could easily include under the hood as well. Basically look at the wiring diagram and ask yourself "how would I go about making this drive away w/o the key?" And look in those areas.
 
I really appreciate all the suggestions, I’ll get into it this weekend and report back, I haven’t found a an accurate FSM yet, so I’ll just consider it diagnostic hard mode. I’ll just feel more accomplished when I get it done, right? :)
 
Jrad1337 said:
I really appreciate all the suggestions, I’ll get into it this weekend and report back, I haven’t found a an accurate FSM yet, so I’ll just consider it diagnostic hard mode. I’ll just feel more accomplished when I get it done, right? :)
Click to expand...

What do you mean you haven't found an accurate FSM yet? Enough of us have been through those things enough times across enough years that we've flushed out most of the problems. Occasionally you'll find something in your jeep that was for the prior model year as things change but it's kinda rare. And every now and then you'll find a wire that's the wrong color according to the FSM but for the most part they're very accurate. Post up those challenges and I bet we can get you squared away.
 
Update: Found an accurate FSM, I ended up chasing wire until I found that the reason the relay isn’t energizing is due to the PCM not providing a ground for terminal 85 of the relay. Next is finding what parameters are needed for the PCM to provide ground?
 
Jrad1337 said:
Update: Found an accurate FSM, I ended up chasing wire until I found that the reason the relay isn’t energizing is due to the PCM not providing a ground for terminal 85 of the relay. Next is finding what parameters are needed for the PCM to provide ground?
Click to expand...

Going to thoroughly check the clutch safety switch circuit again, other than that I’m tapped out. Hopefully not a PCM issue?
 
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